An example of the construction of a prior art switch for use in a power window is shown in FIG. 22. This switch comprises a long common C.sub.c on a power supply side serving as a fixed contact, a pair of manual operation contacts (which are referred to simply as "manual contacts") C.sub.M provided in juxtaposition with both ends thereof, and a pair of shortest auto-operation contacts (which are referred to simply as "auto-contacts") C.sub.A provided in juxtaposition with the end of each of the manual contacts C.sub.M. A sliding contacts C.sub.S attached to an operating knob K.sub.b is sliding disposed on the intermediate portion of the power supply side common C.sub.c so that the contact C.sub.S may be brought by the knob K.sub.b into contact with either one of the left and right hand manual contacts C.sub.M or with both of either one of the manual contacts C.sub.M and either one of the auto-contacts C.sub.A. The operating knob K.sub.b can be used to change the upward movement of the window glass over to downward movement or vice versa depending on the direction of movement of the knob. For the sake of convenience of the following description, in this drawing, the counterclockwise swing of the knob shall be referred to as "up-side" swing, and the clockwise swing thereof as "down-side" swing. Further, the knob K.sub.b is biased by a spring to return to its neutral position, if the operator's hand is removed from the knob which is in swinging condition. The left and right hand manual contacts C.sub.M are connected through relays R.sub.UP and R.sub.DWN, respectively, which are normally grounded, with a window motor M. The left and right hand auto-contacts C.sub.A are connected through an auto-condition retaining circuit A.R.C with the relays R.sub.UP and R.sub.DWN, respectively.
When the knob K.sub.b is moved to contact the sliding contact C.sub.S with either one of the left and right hand manual contacts C.sub.M, the switch will assume either a manual-up position M.sub.UP or a manual-down position M.sub.DWN. Only while the knob K.sub.b is held at this position, either the relay R.sub.UP or the relay R.sub.DWN is energized so as to connect it with the power supply to rotate the window motor M forward or backward so that upward or downward movement of the window glass can be manually conducted.
When the knob K.sub.b is moved further to contact the sliding contact C.sub.S with either one of the left and right hand manual contacts C.sub.M and either one of the left and right hand auto-switches C.sub.A, the switch will assume either an auto-up position AT.sub.UP or an auto-down position AT.sub.DWN so that, even when the operator's hand is removed from the knob K.sub.b to return it to its neutral position N, electric current flowing through either one of the auto-switches C.sub.A Will allow the auto-condition retaining circuit A.R.C to assume auto-operating condition thus holding either the relay R.sub.UP or the relay R.sub.DWN in operative condition. Consequently, the window motor M is allowed to rotate continuously, When the window glass is opened or shut to its full extent shortly, the window motor M is stopped, and the sensor which detects the stopping of it will release the auto-condition, thereby turning off electricity to the window motor M. Thus, since the arrangement is made such that depending on the amount of movement of the operating knob either the manual operation or the auto-operation can be re-elected as desired, it is only necessary to provide only one piece of the knob so that the structure of the switch can be simplified and also it can be operated easily.
However, when the relay R.sub.UP is held in auto-condition, for example, if the knob K.sub.b, which has been returned to its neutral position N, is moved to the manual-down position M.sub.DWN on the opposite side (reverse manual position), then the auto-condition retaining circuit A.R.C. will release the auto-up condition, and the relay R.sub.DWN is rendered operative after a predetermined time.
An example of the auto-switch adapted to hold the window glass in the auto-condition by means of such a relay is described also in U.S. Pat. No. 4,709,196.
Further, in the following description, upward and downward movements of the window glass by such a manual operation are referred to as manual-up and manual down, respectively, and upward and downward movements of the window glass by such auto-operations as auto-up and auto-down, respectively.
This auto-switch, which enables both the manual operation and the auto-operations to be conducted, is mounted on a door of a motor vehicle by a driver seat, while a manual switch which can be actuated only by manual operation is mounted on each of the remaining doors. As the manual switch of the kind specified above, a reverse switch is sometimes used, which comprises a pair of V-shaped swing contact plates each having a normally-open movable contact and a normally-closed movable contact provided on both ends thereof, the arrangement being made such that either one of the swing contact plates is inclined reversely by swinging the knob, depending on the direction of swing thereof (such a manual switch is described, for example, in U.S. Pat. No. 4,803,317).
Incidentally, since the auto-switch utilizing the above-mentioned relay circuit requires a comparatively large space for mounting the relays R.sub.UP and R.sub.DWN on the up and down sides thereof, it is difficult to assemble these relays integrally in the switch for a power window fitted to a door of a motor vehicle. Therefore, the switch and the circuit/relay must be mounted separately, thus increasing the number of attaching operations to the doors of the motor vehicle, and also increasing the restrictions in terms of space for mounting. Moreover, the separate mounting resulted in increases in the number of parts and the weight, thus increasing the cost. For this reason, it has been desired strongly to make the auto-switch as light- weight and compact as possible by forming it in such a construction which needs not use such relays.
Further, auto-switches which use a solenoid in place of relays are shown in, for example, U.S. Pat. Nos. 4,376,896 and 4,540,965, etc. However, all of these auto-switched are arranged to hold an operating knob, which is swung to an auto-position and held in a swinging condition, in auto-condition. In order to release the auto-condition at any desired position, a strong force must be applied to the knob to move it back to its neutral position and open the contacts compulsorily. Therefore, it was impossible to operate the knob for releasing the auto-condition at a desired position with the same feeling as that in operating it in the normal operation.
Accordingly, the present invention has for its principal object to provide an auto-switch which is capable of stopping the rotation of the window motor in the auto-condition at any desired position by operating the knob with the same feeling as that in operating it in the normal operation so that the operability of the knob is enhanced.